Capacitors are utilized in a whole range of electronic circuits, both digital and analog, for the purpose of storing electricity or electrical energy. Capacitors also function as a filter, passing alternating current (AC), and blocking direct current (DC).
An ever increasing trend of downscaling of electronic components has led to a demand for discrete capacitors which have smaller dimensions but the same large capacitance values and which can be manufactured using thin file fabrication techniques suitable for integrating such capacitors into micro electronic devices, such as semiconductor chip devices, or other devices used in micro or nano technologies.
A variety of types of capacitors and methods of fabrication have been employed to date. One such capacitor is a Metal-Insulator-Metal (MIM) capacitor, typically used in CMOS, RF and other applications, which consists of a planar structure having a thin dielectric layer sandwiched between two metallic electrodes or plates. MIM capacitors are usually fabricated as a stack of layers in semiconductor device wafers by sequentially forming a patterned metal layer, an insulator layer thereon and another patterned metal layer on the insulator layer. Fabrication of the MIM insulator and top layer metal require separate lithographic mask sets, as well as additional steps through processing making the wafers containing MIM capacitors costly to produce. Furthermore, a significant amount of spacing between other metal layers is required resulting in a larger proportion of valuable chip area being required to accommodate the MIM capacitors.
Connection points for MIM and other existing capacitors are on two different sides of the device which can lead to difficulty when connecting them to other circuitry, especially if the circuitry has a very dense layout where surface area is scarce.
There is a continuing need to provide capacitors utilized in integrated circuit or discrete circuit applications which can be manufactured and integrated into circuits more efficiently.
The embodiments disclosed herein therefore directly address the shortcomings of present capacitors providing a plate to plate capacitor that can be integrated more effectively into integrated circuit applications or other discrete circuit applications.